Photograph



M. B. PEAL.

PHONOGRAPH.

- APPLICATION FILED APR.20| 191s.

mm'mm Patented June 17, 1919.

imparting relatively quick swinging move- 7 'irn' swans MARSHALL B. PEAL, F BROOKLYN, NEW YORK.

PHONOGRAPH.

Application filed April 20, 1916. Serial No. 92,564.

To all whom it may concern Be it known that. l, MARSHALL B. PEAL, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Phonographs, of which the following is a specification,

This invention relates to a phonograph, and particularly to means for automatically causing the phonograph to cease all mechanical motion after the stylus or needle has completed its course of travel relatively to the sound producing surface of the record.

A further object is to provide a record having means adapted to cooperate with features embodied in the phonograph structure for causing the rotation of the record to cease after the sound producing surface of the record has been traversed by the stylus or needle.

A. further object is to provide means for ment to the phonograph arm after the stylus carrying the said arm has completed its travel over the sound producing surface of the record.

A more detailed object is to provide a continuation from the sound producing groove in the record adapted to impart a quick swinging movement to the phonograph arm after the stylus has completed its travel of i the sound producing groove.

Further detailed object is to provide sufficient means for retaining the stylus against possible accidental displacement from the continuation of the sound producing groove.

Other objects and aims of the invention, more or less specific than those referred to above, will be in part obvious and in part pointed out in the course of the following description of the elements, combinations, arrangements of parts and applications of principles, constituting the invention; and the scope of protection contemplated will be indicated in the appended claims.

In the accompanying drawings which are to be taken as a part of this specification, and in which I have shown a merely preferred form of embodiment of the invention:

Figure 1 is a top. plan view of a phonograph machine having a record in posit1on thereon, provided with this invention? Fig. 2 is a diagrammatic view illustrating the arrangement and'shape of the groove of the central portion of the disk illustrated in Fig.- 1.

Fig. 3 is an enlarged sectional view or development of the groove constituting one of the essential features of this invention.

Fig. 4 is a, fragmentary sectional view taken transverse of the groove; and

Fig. 5 is a view similar to that shown in Fig. 4, but illustrating a modification.

Referring to the drawings for a detailed description of the structure shown therein,

the reference character L indicates the phonograph disk. The reference character G 1nd1cates the rotatable table common to phonograph construction, and the reference character H indicates the horn arm.

The record disk is adapted to bemounted upon the table G, in the usual manner asillustrated in Fig. 1. I

The table G may be rotated by any suitable mechanism from within the casing A, such mechanism forming no part of this invention.

A suitable brake or stop mechanism is employed in connection with the table G for braking or stopping the rotation of the table. This mechanism may be of any approved type now well known in the art.

' The brake or stop mechanism illustrated The spring t is fixed to the arm 5 to urge the same into an engaging position. The arm 6 of the second bell-crank lever projects into the path of movement of' a lug 7 formed upon the horn H, so that when said 'horn swings inwardly th 111g 7 will engage the arm 6 and move the same to permit the friction element 3 to press against and stop rotation of the table G.

The use of a lug, or the like, carried by the 1 horn arm for engaging a lever to trip a brake mechanism is well known, but heretofore a minute andcareful adjustment has been necessary as between the lug and lever so as to cause the same to properly cooperate in stopping rotation of the disk at the proper point. It has. been necessary in most cases to change the adjustment for each lug 7.

to, the horn arm will be given an accelerated swinging movement just after the music surface of the disk has been traversed. The movement will be through such a sufficiently wide are so that the lug 7 will engage "and operate the arm 6 irrespective of the precise position of the arin, 6 with respect to the The means devlsed fdr accomplishing this i 1 result is best illustrated in the diagrammatic view Fig. 2. It consists of a continuation groove 8 from the innermost convolution of the music groove. The said continuation is made on a curve f gradually diminishing radii. The decrease in radii, however, being much greater than the decrease in radii of the normal music-groove. Preferably, ap-' proximately one turn, or less, of the disk only is required to carry the cdntinuation from the innermost music groove to the innermost point reached by the continuation. Thus if the stylus, as 10, carried by the horn arm has completed its travel of the music groove, approximately one more turn of the disk will guide the stylus rapidly inwardlyto its innermost desired position- In Fig.1 the light dotted lines indicate the angle defined from the center of move. ment of the horn arm in one direction to the stylus andin another direction to the end of lug 7. The heavy dotted lines indicate the position of thisanglewhen thestylus has completed its travel of the music groove,

(note'that thearm 6 of the bell-crank lever has not yet been reached by the h1g7) The heavy dash line indicates the position of the angle after the disk has made approximately one more revolution. has'passed throughthe region of the arm, 6. to a sufficient extentto have caused the operation of said arm.)

y 'In order that the stylus will be caused to travel correctly and easily along the continuation 8, it is part of this invention to provide means for retaining the stylusagainst possible displacement from the groove forming said continuation. This means includes two distinct elements.

First, the idea of so curving the groove that the accelerated swing of the stylus and horn will begin very gradually and will not assume marked proportions until after a sufficient'momentum has been gathered in the horn arm. Thus, approximately-the first quarter of the continuation groove is on almost the same curve as the curve of the than either of the previous quarters.

(Note thatthe. lug 7 J,

. radii. The. third quarter is of more rapidly reducing radii than the-second quarter. The fourth quarter, which will not be reached until a considerable momentum has been gathered in the stylus supporting'parts, is

On a very much more rapidly reducing course the change from one quarter to the next isgradual and smooth, as clearly indicated in Fig. 2.

Second, the idea'of making the continuation groove of varying depths in accordance with the resistance required to prevent displacement of the stylus at the successively advancing portions of said groove. This changing depth is clearly indicated in the development of Fig. 3. At the right hand side of said figure the space between'A and B corresponds with the space between the same letters in Fig. 2. The groove in this portion is of substantially the same depth as the music groove. The space between the letters B and 0 corresponds with the space between the same letters in Fig. 2'. The inward movement of the stylus begins to be accelerated in this space and accordingly, the groove is gradually deepened until at C it reaches its maximum depth. From C to D the inward movement of the stylus is gradually accelerated and a certain degree of momentum is picked up, so that the depth of the groove may be gradually diminished, as indicated. s above stated, the throw or swing of the horn from the position shown by the heavy dotted lines in Fig. 1 to the position shown by the heavy dash lines in said figure,

jis intended'to operate the automatic stop mechanism. At 11in Figs. 1 and 2, however, a groove is illustratedwhich is adapted to receive the stylus in case the automatic stop should for any reason not operate.

-Groove 11 is circular so that the stylus would continue'to traverse the same without swingg the horn until the rotation of the disk was stopped. z

The depth of the groove 11 is preferably constant, as shown between the letters .D and E in Fig. 3.

In Fig. 5 a modification is illustrated in which an embankment 12 is shown as a substitute for deepening the groove. The embankment is arranged to receive lateral pressure from the stylus in the same manner as would the walls of a'deepened groove. The actual depth of the groove in this instance may be maintained the same as the normal music groove, if desired, Or the embankment 12 may be employed in connection with the deepened grooveif preferred.

Record disks provided with a continuation groove, as above described, may be employed on any of the usual types of disk phonographs, and will operate to control the automatic stops of such machines without necessity for adjustment of any of the parts of such automatic stops.

Although it is preferable that the extension 8 be made directly in the material of the disk in the same manner as are the ordinary music grooves, nevertheless, it will be obvious that a sheet of material might readily be pasted, or'otherwise attached, to the disk, and said sheet be provided with the groove 8, if desired. This method may be employed to some advantage -in connection with the records which have already been manufactured in the usual manner.

As many changes could be made in this construction without departing from the scope of the following claims, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative only and not in a limiting sense.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. Aphonograph record disk having the usual convolute music groove therein for receiving the stylus, said disk being formed with an inwardly projecting extension groove continuing from the inner end of the'music groove also for the travel of the stylus substantially for the purpose set forth, the extension groove being also convolute but being curved on a more rapidly reducing rad-ii Within the radii of successive portions of the 'musicgroove so as to accelerate the inward movement of the stylus, the portion of the a I 2 A phonograph record disk having-the usual convolute music groove thereinfor receiving the stylus, said disk'being formed with an inwardly projecting extension groove continuing from the inner end of the music groove also for the travel of the stylus substantially for the purpose set forth, the

extension groove being also convolute but be ng curved on a more rapidly reduclng radii than the radii of successive portions of .the muslc groove so as to accelerate the 1nward movement of the stylus, and means embodied in the form and disposition of said extension groove relativelyto the music groove effective to prevent accidental disengagement-of the stylus from the extension groove in proportion to the tendency of the stylus to leave the extension groove at successive points in the length of the extension 65 groove.

In testimony whereof I aflix my signature in the presence of two witnesses.

MARSHALL B. PEAL.

' Witnesses: I

L. GEssroRD HANDY, GUSTAV YLGENZLINGER. 

